Tone-producer for fire-alarm-box mechanisms.



IL-G. DEE. TONE PRODUCER FOR FIRE ALARM Box MECHANISMS.

I APPLICATION FILED APR. 23. I9I'4- Patented May 29, I917.

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UNITED STATES PATEN ore DAVID G. DEE, or ROCHESTER, NEWIQRK, AssIG oE, BY iviEsNE ASSIGNMENTS, To oonEsrEn H. EoGEEs, or ROGHESTER, NEW yogam I T'ONE-PRQ'DUCER Eon rrnE-ALAEM-Eox MEcHAnIsMs.

Toall'wkom it may. concern;

Be it known that-'1', Rochester,

new and useful Improvements" in Tone -Producers for Fire-Alarm -Box Mechanisms; declare the following to-be a full, clear, and: exact description of the:

and I do hereby same, reference being had to the accompanying drawings, fication, and to the reference-numerals marked thereon. V

. My present inventionhas for its object to provide-a tone' producing; magnet and armature adapted to be used particularly'in conjunction with mechanisms employed for transmitting fire alarmoalls or signals-over the subscribers lines of telephone exchange systems whereby a distinctive signal-can be transmitted, in addition to the impulses of current despatched, so'that the central oflice operator may immediately recognize and dis-' tinguish the operation of said mechanism from other disturbances which occur upon the line. 7 To these and other endsthe invention consists in certain improvements and In the operation of. fire alarm signal mechanisms which are to be used in conjunc-- tion with telephone subscribers circuits it' is essential that provision be made whereby the central oflice operator when she observes an incoming signal= should be'informedof its precise: character and that she be able to quickly determine that the flashing: of the pilot" light of'the switchboard is due to the transmission of the fire alarm' impulses. This knowledge on the part of the operator enables herto connect the signaling line with fire department headquarters immediately without waiting until: the alarm box mechanism has rung in its full round or complete code number. Inmy present apparatus I haveprovided means whereby an alternating: current is superimposed on the Specification of Letters Patent.

IDLAIVIIJ) Gn-DEE, of in the county of Monroe and State of New York, have'invented certainforming a part of this speci I Patented May 29', 1917.

Application filed April 23, 1914. Serial N 0. 833,857.

tions inthe potential of-the flow of the battery current are efl'ected to produce the alarm impulses whichlatter actuate the sounding and recording devices at the fire department headquarters. I v

Mechanism embodying my invention is applicable to any desired'typeof code impulse transmitting. apparatus, and the one I have illustrated for the purpose offacilitating. the descriptioncomprises an arbor 1 rotated by a spring driven clock train'carrying the code wheel 2 provided with notches or teeth, as shown, cocperating with the finger 3 by. meansof which pairs of contacts 4 and 5 are alternately opened and closed. The clock train is normally prevented from movement by the restraining device such as These parts. are preferably mounted on a base or backing 12 which also serves as a support for the magnet coil, its armature and the vibrator attached thereto with which the hammer ooiiperates. The magnet coil 13 is wound in the usual mannerupon a'c0reand it is supported by a screw 14 entering one end of said core and passing through a plate 15 which projects forwardly from the base ;12- and is provided with a laterally' extending flange 16' resting upon said base and secured thereto by screws 17 The armature for the magnet is preferably formedby making the plate 15 of suflicient length to permit it to be bent horizontally, as indicated-at- 18, and again vertically, as indicated at 19,the upper end of the portion 19-1'ying in front of the free end of the 'core of the'magnet and preferably providedwith an enlarged head or boss 20 into which is rigidly secured a. vibrating member "consisting; in the present instance, of a spiral spring 21 ,a portion of whichis so positioned relatively toflthe hammer 11 that upon each movement of the latter it will be caused to Vibrate, the vibratory motion of which is imparted-t0 the. armaturel9;

Theessential feature of my invention resides in the manner in which the armature ismadeand the means by which it is adjus'ted. In order to obtain the most satisfactory results from the vibrations of the armature 19 I deem it essential that the latter shall be under molecular tension and to this end in the formation of the parts 15, 18 and 19 I bend them so that the distance between the upper end of the armature 19 and its support or plate 15 is less than the length of the core of the magnet and 1 then separate these parts by an adjusting screw 22. The end 23 of the screw is threaded in the plate 15, while its opposite extremity bears against the armature 19 and forces it laterally the required distance. The action of the screw 22 is one forcing the armature 19 by the pressure exerted against it which, in practice, I find produces far better results than can be obtained when the parts are so constructed that the armature must be drawn into the desired position by a tension screw.

In order to illustrate the operation of the mechanism 1 have shown it associated with a telephone subscribers instrument circuit comprising the line wires A and B leading to the terminals of the switchboard jack J, said circuit comprising the transmitter T and receiver R. The contact springs 5 and 5 are normally held in engagement and close the subscribers circuit when the receiver is removed from the hook, through the transmitter T, as indicated by the wires on and a. The alarm mechanism is included in the telephone circuit by the wire Z) connected to one termlnal of the magnet coil 13 and the wire 6 leading from the other extremity of said coil to the contact spring a which, it will be understood, cooperates with the spring 5 when the latter is released by the operation of the alarm box mechanism.

The central office apparatus or switchboard mechanism may be of the usual or any preferred construction and for the purposes of illustration 1 have shown the answering and calling cord circuits as comprising the plugs G and D respectively, sup-- plied with current from battery X, and with which is associated the operators telephone set comprising the receiver E and the transmitter F. The switchboard mechanism also comprises a pilot light 3', the circuit of which is closed by the springs of the jack J when these are in their normal position, affording means for the lighting of the operators lamp or signal when the subscribers circuit is closed. It is customary in fire alarm systems in which signal box mechanism of this kind is employed to provide on the switch board at each operators station what is known as a fire plug from the contacts of which conductors lead to the fire department headquarters. This plug isindicated by S and the circuit is shown as comprising the wires 8, s which include a local battery 8 and a repeater relay 8 the armature s of which controls the fire alarm register circuit comprising the wires 8 and s, the local battery s and the register mechanism 8 In the operation of the apparatus the closing together of the the alarm mechanism across the subscribers circuit and causes the lighting of the pilot lamp j which flickers and winks in response to the impulses of current transmitted by the code wheel 2. At the same time the rotation of the ratchet wheel 9 causes a rapid oscillation of the hammer 11 which establishes a high rate of vibratory movement in the armature 19, causing the latter to change the air gap between it and the pole of the magnet 13 and thus vary the magnetic flux of the core of said magnet. The central office operator in perceiving the operation of the pilot light j first tests the line by inserting the answering plug C in the jack J, whereupon she hears the distinctive signal or tone, which in the particular type of apparatus illustrated is very similar to the sound of a clock spring gong and knowing the purpose of this tone, she immediately substitutes the fire plug S for the answering plug C, and following this action the alarm impulses from the code wheel 2 are reproduced on the recording apparatus 8 at fire alarm headquarters.

The integral construction of the armature and its support permits these parts to be made not only with the requisite accuracy, but also to be assembled with the magnet 13 and adjusting screw 22 in position, so that all of these elements may be mounted on the base 12 and secured at once by the screws or positioning devices 17. By reason of the initial tension placed in the armature 19, by bending it in the manner described and then moving it into its normal operative position by the screw 22, I am able to provide an armature which is under a constant uniform tension and that may be adjusted toward and from the magnet core without employing springs or other devices for yieldingly holding it in operative position.

I claim as my invention 1. In a tone producer the combination with an electromagnet, of a support therefor, an armature carried by said support, means for flexing said armature to bring it into operative position relatively to said magnet, said means also serving to hold the armature in its adjusted position, and automatic means for vibrating the armature.

2. In a tone producer the combination with a support, of an electromagnet mounted thereon and an armature also fixed to said support and having a normal tendency to move in a direction toward said magnet, means for adjusting it away from said magnet, and means for imparting periodic vibratory action to the armature.

springs 4 and 5 bridges 3. In a tone producer, the combination with a member having a supporting portion and an armature positioned opposite thereto and a member operating against said support and said armature to separate them and impart a tension to the armature, of an electromagnet mounted between the support and armature and means for vibrating the latter.

4. In a tone producer, the combination with a U-shaped metallic member comprising a supporting portion having an attaching flange at one edge and an end forming an armature, of an electromagnet mounted on the supporting portion, said armature end being initially bent toward the supportingportion and occupying a position in proximity thereto less than the length of the magnet, means for forcing the armature outwardly a distance greater than the length of said magnet and holding it in this position and means for vibrating the armature.

5. In a tone producer the combination with an electro-magnet, of a support there for, an armature carried by and forming an integral part of said support, means for flexing said armature to bring it into operative position relative to said magnet, and mechanical means for automatically vibrating said armature.

6. In a tone producer the combination with a support comprising a plate provided with a laterally projecting attaching flange at one end, said plate having its bent end bent at right angles in several places so that it rests approximately parallel to that portion provided with said flange, and an electromagnet secured to the portion of said' plate carrying the flange, the free end of said plate constituting an armature therefor.

7. The combination with an electromag netic coil, of an armature therefor, a sound device earned at the free terminal of said coil, and means adapted to periodically contact with the sound device for the vibration thereof together with the armature aforesaid.

netic coil, of an armature therefor, a sound device secured to said armature, a hammer, and means for periodically striking the hammer against the sound device for the vibra- 8. The combination with an electromagtion thereof together with the armature DAVID e. DEE.

Witnesses:

CHAS. R. PEEL, MAE C. ONEILL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

